余甘子酚类成分及其抑制α-葡萄糖苷酶活性的研究

Structural Identification of Phenolic Constituents from Phyllanthus emblica L. and Their Inhibitory Activity on α-glucosidase

摘要:

研究余甘子甲醇提取物降糖活性部位中的酚类化学成分及其抑制α-葡萄糖苷酶活性。采用甲醇浸泡提取余甘子，D101大孔树脂柱粗分离得到三个部位，降糖活性测试表明30%乙醇洗脱部位(PEA)为活性部位，后续采用Sephadex LH-20，ODS和制备HPLC等柱色谱技术对其进行分离纯化，根据化合物理化性质、NMR和HR-ESI-MS数据并参考相关文献鉴定化合物结构，采用体外方法测定化合物抑制α-葡萄糖苷酶活性。从PEA部位中分离并鉴定了7个酚类化合物，分别为：没食子酸(1)，没食子酸甲酯(2)，1-O-没食子酰基-β-D-葡萄糖苷(3)，1,6-二-O-没食子酰基-β-D-葡萄糖苷(4)，柯里拉京(5)，粘酸-1,4-内酯-2-O-没食子酸酯(6)，粘酸-2-O-没食子酸酯(7)。除化合物2外所有化合物均具有一定的抑制α-葡萄糖苷酶活性。没食子酸衍生物是余甘子抑制α-葡萄糖苷酶活性成分。

Abstract:

The phenolic constituents in the hypoglycemic active fraction of the methanol extract of Phyllanthus emblica L and their inhibitory activity on α-glucosidase were studied. Using methanol soaking extract Phyllanthus emblica L, the methanol extract (PE) was chromatographed on a D101 macroporous resin column to obtain three fractions (PEA-PEC). Hypoglycemic activity test showed that 30% ethanol elution part (PEA) was the active fraction. PEA was further isolated and purified by column chromatography of Sephadex LH-20, ODS and semi-preparative HPLC columns. The structures of the isolated compounds were identified according to the physicochemical properties, 1H-NMR, 13C-NMR and high resolution mass spectral analyses as well as relevant references. The compounds were tested for their in vitro inhibitory activity on α-glucosidase. Seven phenolic compounds were isolated from PEA fraction and identified as gallic acid (1), methyl gallate (2), 1-O-galloyl-β-D-glucose (3), 1,6-di-O-galloyl-β-D-glucose (4), corilagin (5), mucic acid-1,4-Lactone-2-O-gallate (6), mucic acid-2-O-gallate (7). All compounds except compound 2 showed good inhibitory activity on α-glucosidase. Gallic acid derivatives were the active constituents that P. emblica L inhibited the activity of α-glucosidase.